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We study the dependence of star formation quenching on galaxy mass and environment, in the Sloan Digital Sky Survey (SDSS; z ∼ 0.1) and the All-Wavelength Extended Groth Strip International Survey (AEGIS; z ∼ 1). It is crucial that we define quenching by low star formation rate rather than by red colour, given that one-third of the red galaxies are star forming. We address stellar mass M*, halo mass Mh, density over the nearest N neighbours δN and distance to the halo centre D. The fraction of quenched galaxies appears more strongly correlated with Mh at fixed M* than with M* at fixed Mh, while for satellites quenching also depends on D. We present the M*–Mh relation for centrals at z ∼ 1. At z ∼ 1, the dependence of quenching on M* at fixed Mh is somewhat more pronounced than at z ∼ 0, but the quenched fraction is low (10 per cent) and the haloes are less massive. For satellites, M*-dependent quenching is noticeable at high D, suggesting a quenching dependence on subhalo mass for recently captured satellites. At small D, where satellites likely fell in more than a few Gyr ago, quenching strongly depends on Mh and not on M*. The Mh dependence of quenching is consistent with theoretical wisdom where virial shock heating in massive haloes shuts down accretion and triggers ram-pressure stripping, causing quenching. The interpretation of δN is complicated by the fact that it depends on the number of observed group members compared to N, motivating the use of D as a better measure of local environment. [ABSTRACT FROM AUTHOR]

We present the mid-infrared (MIR) properties of galaxies within a supercluster in the north ecliptic pole region at z ~ 0.087 observed with the AKARI satellite. We use data from the AKARI NEP-Wide (5.4 deg²) IR survey and the CLusters of galaxies EVoLution studies (CLEVL) mission program. We show that near-IR (3 µm)-mid-IR (11 µm) color can be used as an indicator of the specific star formation rate and the presence of intermediate-age stellar populations. From the MIR observations, we find that red-sequence galaxies consist not only of passively evolving red early-type galaxies, but also of (1) "weak-SFGs" (disk-dominated star-forming galaxies that have star formation rates lower by ~4 x than blue-cloud galaxies) and (2) "intermediate-MXGs" (bulge-dominated galaxies showing stronger MIR dust emission than normal red early-type galaxies). These two populations can be a set of transition galaxies from blue, star-forming, late-type galaxies evolving into red, quiescent, early-type ones. We find that the weak-SFGs are predominant at intermediate masses (1010 M⊙ < M* < 1010.5 M⊙) and are typically found in local densities similar to the outskirts of galaxy clusters. As much as 40% of the supercluster member galaxies in this mass range can be classified as weak-SFGs, but their proportion decreases to <10% at larger masses (M* > 1010.5 M⊙) at any galaxy density. The fraction of the intermediate-MXG among red-sequence galaxies at 1010 M⊙ < M* < 1011 M⊙ also decreases as the density and mass increase. In particular, ~42% of the red-sequence galaxies with early-type morphologies are classified as intermediate-MXGs at intermediate densities. These results suggest that the star formation activity is strongly dependent on the stellar mass, but that the morphological transformation is mainly controlled by the environment. [ABSTRACT FROM AUTHOR]

ABSTRACT Using data drawn from the DEEP2 and DEEP3 Galaxy Redshift Surveys, we investigate the relationship between the environment and the structure of galaxies residing on the red sequence at intermediate redshift. Within the massive (10 < log10( M★/ h−2 M⊙) < 11) early-type population at 0.4 < z < 1.2, we find a significant correlation between local galaxy overdensity (or environment) and galaxy size, such that early-type systems in higher density regions tend to have larger effective radii (by ∼0.5 h−1 kpc or 25 per cent larger) than their counterparts of equal stellar mass and Sérsic index in lower density environments. This observed size-density relation is consistent with a model of galaxy formation in which the evolution of early-type systems at z < 2 is accelerated in high-density environments such as groups and clusters and in which dry, minor mergers (versus mechanisms such as quasar feedback) play a central role in the structural evolution of the massive, early-type galaxy population. [ABSTRACT FROM AUTHOR]

ABSTRACT We present measurements of projected autocorrelation functions wp( rp) for the stellar mass of galaxies and for their light in the U, B and V bands, using data from the third data release of the DEEP2 Galaxy Redshift Survey and the final data release of the Sloan Digital Sky Survey (SDSS). We investigate the clustering bias of stellar mass and light by comparing these to projected autocorrelations of dark matter estimated from the Millennium Simulations (MS) at z= 1 and 0.07, the median redshifts of our galaxy samples. All of the autocorrelation and bias functions show systematic trends with spatial scale and waveband which are impressively similar at the two redshifts. This shows that the well-established environmental dependence of stellar populations in the local Universe is already in place at z= 1. The recent MS-based galaxy formation simulation of reproduces the scale-dependent clustering of luminosity to an accuracy better than 30 per cent in all bands and at both redshifts, but substantially overpredicts mass autocorrelations at separations below about 2 Mpc. Further comparison of the shapes of our stellar mass bias functions with those predicted by the model suggests that both the SDSS and DEEP2 data prefer a fluctuation amplitude of σ8∼ 0.8 rather than the σ8= 0.9 assumed by the MS. [ABSTRACT FROM AUTHOR]

We present the analysis of Herschel Spectral and Photometric Imaging Receiver far-infrared (FIR) observations of the z = 2.515 tensed galaxy SMM J163554.2+661225. Combining new 250, 350, and 500 µm observations with existing data, we make an improved fit to the FIR spectral energy distribution of this galaxy. We find a total infrared (IR) luminosity of L(8-1000 µm) =6.9 ± 0.6 x 1011 L⊙, a factor of three more precise over previous LIR estimates for this galaxy, and one of the most accurate measurements for any galaxy at these redshifts. This FIR luminosity implies an unlensed star formation rate (SFR) for this galaxy of 119 ± 10 M⊙ yr-1, which is a factor of 1.9 ± 0.35 lower than the SFR derived from the nebular Paα emission line (a 2.5σ discrepancy). Both SFR indicators assume an identical Salpeter initial mass function (IMF) with slope Γ = 2.35 over a mass range of 0.1-100 M⊙; thus this discrepancy suggests that more ionizing photons may be necessary to account for the higher Paα-derived SFR. We examine a number of scenarios and find that the observations can be explained with a varying star formation history (SFH) due to an increasing SFR, paired with a slight flattening of the IMF. If the SFR is constant in time, then larger changes need to be made to the IMF by either increasing the upper mass cutoff to ~200 M⊙, or a flattening of the IMF slope to 1.9 ± 0.15, or a combination of the two. These scenarios result in up to double the number of Stars with masses above 20 M⊙, which produce the requisite increase in ionizing photons over a Salpeter IMF with a constant SFH. [ABSTRACT FROM AUTHOR]

We present a study characterizing the environments of galaxies in the redshift range of based on data from the POWIR near-infrared imaging and DEEP2 spectroscopic redshift surveys, down to a stellar mass of . Galaxy environments are measured in terms of nearest-neighbour densities as well as fixed aperture densities and kinematical and dynamical parameters of neighbour galaxies within a radius of Mpc. We disentangle the correlations between galaxy stellar mass, galaxy colour and galaxy environment, using not only galaxy number densities, but also other environmental characteristics such as velocity dispersion, mean harmonic radius and crossing time. We find that galaxy colour and the fraction of blue galaxies depends very strongly on stellar mass at , while a weak additional dependence on local number densities is in place at lower redshifts . This environmental influence is most visible in the colours of intermediate-mass galaxies , whereas colours of lower- and higher-mass galaxies remain largely unchanged with redshift and environment. At a fixed stellar mass, the colour-density relation almost disappears, while the colour-stellar mass relation is present at all local densities. We find a weak correlation between stellar mass and environment at intermediate redshifts, which contributes to the overall colour-density relation. We furthermore do not find a significant correlation between galaxy colour and virial mass, i.e. parent dark matter halo mass. Galaxy stellar mass thus appears to be the crucial defining parameter for intrinsic galaxy properties such as ongoing star formation and colour. [ABSTRACT FROM AUTHOR]

Using galaxy samples drawn from the Sloan Digital Sky Survey and the DEEP2 Galaxy Redshift Survey, we study the relationship between star formation and environment at and 1. We estimate the total star formation rate (SFR) and specific star formation rate (sSFR) for each galaxy according to the measured [O ii]λ 3727 Å nebular line luminosity, corrected using empirical calibrations to match more robust SFR indicators. Echoing previous results, we find that in the local Universe star formation depends on environment such that galaxies in regions of higher overdensity, on average, have lower SFRs and longer star formation time-scales than their counterparts in lower density regions. At , we show that the relationship between sSFR and environment mirrors that found locally. However, we discover that the relationship between total SFR and overdensity at is inverted relative to the local relation. This observed evolution in the SFR–density relation is driven, in part, by a population of bright, blue galaxies in dense environments at . This population, which lacks a counterpart at , is thought to evolve into members of the red sequence from to ∼0. Finally, we conclude that environment does not play a dominant role in the cosmic star formation history at : the dependence of the mean galaxy SFR on local galaxy density at constant redshift is small compared to the decline in the global SFR space density over the last 7 Gyr. [ABSTRACT FROM AUTHOR]

We study the mean environment of galaxies in the DEEP2 Galaxy Redshift Survey as a function of rest-frame colour, luminosity, and [O ii] 3727 Å equivalent width. The local galaxy overdensity for >14 000 galaxies at is estimated using the projected third-nearest-neighbour surface density. Of the galaxy properties studied, mean environment is found to depend most strongly on galaxy colour; all major features of the correlation between mean overdensity and rest-frame colour observed in the local universe were already in place at . In contrast to local results, we find a substantial slope in the mean dependence of environment on luminosity for blue, star forming galaxies at , with brighter blue galaxies being found on average in regions of greater overdensity. We discuss the roles of galaxy clusters and groups in establishing the observed correlations between environment and galaxy properties at high redshift, and we also explore the evidence for a ‘downsizing of quenching’ from to ∼0. Our results add weight to existing evidence that the mechanism(s) that result in star formation quenching are efficient in group environments as well as clusters. This work is the first of its kind at high redshift and represents the first in a series of papers addressing the role of environment in galaxy formation at . [ABSTRACT FROM AUTHOR]

We describe the NIRSpec component of the JWST Deep Extragalactic Survey (JADES), and provide deep spectroscopy of 253 sources targeted with the NIRSpec micro-shutter assembly in the Hubble Ultra Deep Field and surrounding GOODS-South. The multi-object spectra presented here are the deepest so far obtained with JWST, amounting to up to 28 hours in the low-dispersion (R~30–300) prism, and up to 7 hours in each of the three medium-resolution R ≈ 1000 gratings and one high-dispersion grating, G395H (R ≈ 2700). Our low-dispersion and medium-dispersion spectra cover the wavelength range 0.6–5.3 μm. We describe the selection of the spectroscopic targets, the strategy for the allocation of targets to micro-shutters, and the design of the observations. We present the public release of the reduced 2D and 1D spectra, and a description of the reduction and calibration process. We measure spectroscopic redshifts for 178 of the objects targeted extending up to z = 13.2. We present a catalogue of all emission lines detected at S/N > 5, and our redshift determinations for the targets. Combined with the first JADES NIRCam data release, these public JADES spectroscopic and imaging datasets provide a new foundation for discoveries of the infrared universe by the worldwide scientific community. [ABSTRACT FROM AUTHOR]

The Near Infrared Camera for the James Webb Space Telescope (JWST) is delivering the imagery that astronomers have hoped for ever since JWST was proposed back in the 1990s. In the Commissioning Period that extended from right after launch to early 2022 July, NIRCam has been subjected to a number of performance tests and operational checks. The camera is exceeding prelaunch expectations in virtually all areas, with very few surprises discovered in flight. NIRCam also delivered the imagery needed by the Wavefront Sensing Team for use in aligning the telescope mirror segments. [ABSTRACT FROM AUTHOR]

Outflowing winds of multiphase plasma have been proposed to regulate the buildup of galaxies, but key aspects of these outflows have not been probed with observations. By using ultraviolet absorption spectroscopy, we show that "warm-hot" plasma at 105.5 kelvin contains 10 to 150 times more mass than the cold gas in a post-starburst galaxy wind. This wind extends to distances > 68 kilopersecs, and at least some portion of it wit[ escape. Moreover, the kinematical correlation of the cold and warm-hot phases indicates that the warm-hot plasma is related to the interaction of the cold matter with a hotter (unseen) phase at >>106 kelvin. Such multiphase winds can remove substantial masses and alter the evolution of post-starburst galaxies. [ABSTRACT FROM AUTHOR]

We present the discovery of seven X-ray emitting groups of galaxies selected as extended X-ray sources in the 200-ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). In addition, we report on active galactic nucleus (AGN) activity associated with these systems. For the six extended sources which lie within the Deep Extragalactic Evolutionary Probe 2 (DEEP2) Galaxy Redshift Survey coverage, we identify optical counterparts and determine velocity dispersions. In particular, we find three massive high-redshift groups at , one of which is at , the first X-ray detections of spectroscopically selected DEEP2 groups. We also present a first look at the and scaling relations for high-redshift massive groups. We find that the properties of these X-ray selected systems agree well with the scaling relations of similar systems at low redshift, although there are X-ray undetected groups in the DEEP2 catalogue with similar velocity dispersions. The other three X-ray groups with identified redshifts are associated with lower mass groups at and together form part of a large structure or ‘supergroup’ in the southern portion of the AEGIS field. Similar to other X-ray-luminous groups, all of the low-redshift systems are centred on massive elliptical galaxies, and all of the high-redshift groups have likely central galaxies or galaxy pairs. Interestingly, the central galaxies in the highest redshift system show indications of ongoing star formation. All of the central group galaxies host X-ray point sources, radio sources and/or show optical AGN emission. Particularly interesting examples of central AGN activity include a bent-double radio source plus X-ray point source at the centre of a group at , extended radio and double X-ray point sources associated with the central galaxy in the lowest redshift group at , and a bright green valley galaxy (part of a pair) in the group which shows optical AGN emission lines. [ABSTRACT FROM AUTHOR]

The detection of numerous and relatively bright galaxies at redshifts z > 9 has prompted new investigations into the star-forming properties of high-redshift galaxies. Using local forms of the initial mass function (IMF) to estimate stellar masses of these galaxies from their light output leads to galaxy masses that are at the limit allowed for the state of the Lambda Cold Dark Matter (ΛCDM) Universe at their redshift. We explore how varying the IMF assumed in studies of galaxies in the early universe changes the inferred values for the stellar masses of these galaxies. We infer galaxy properties with the spectral energy distribution (SED) fitting code Prospector using varying IMF parameterizations for a sample of 102 galaxies with photometry from the James Webb Space Telescope, JWST Advanced Deep Extragalactic Survey that are spectroscopically confirmed to be at [Formula: see text], with additional photometry from the JWST Extragalactic Medium Band Survey for twenty-one of the galaxies. We demonstrate that models with stellar masses reduced by a factor of three or more do not affect the modeled SED., Competing Interests: Competing interests statement:The authors declare no competing interest.

The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z ≈ 13 (refs. 1-3 ). In addition, the discovery of many luminous galaxies at Cosmic Dawn (z > 10) has suggested that galaxies developed rapidly, in apparent tension with many standard models 4-8 . However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain. Here we present JWST Advanced Deep Extragalactic Survey-Near-Infrared Spectrograph spectroscopic confirmation of two luminous galaxies at z = 14.32 - 0.20 + 0.08 and z = 13.90 ± 0.17. The spectra reveal ultraviolet continua with prominent Lyman-α breaks but no detected emission lines. This discovery proves that luminous galaxies were already in place 300 million years after the Big Bang and are more common than what was expected before JWST. The most distant of the two galaxies is unexpectedly luminous and is spatially resolved with a radius of 260 parsecs. Considering also the very steep ultraviolet slope of the second galaxy, we conclude that both are dominated by stellar continuum emission, showing that the excess of luminous galaxies in the early Universe cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history., (© 2024. The Author(s).)

Several theories have been proposed to describe the formation of black hole seeds in the early Universe and to explain the emergence of very massive black holes observed in the first thousand million years after the Big Bang 1-3 . Models consider different seeding and accretion scenarios 4-7 , which require the detection and characterization of black holes in the first few hundred million years after the Big Bang to be validated. Here we present an extensive analysis of the JWST-NIRSpec spectrum of GN-z11, an exceptionally luminous galaxy at z = 10.6, revealing the detection of the [NeIV]λ2423 and CII*λ1335 transitions (typical of active galactic nuclei), as well as semi-forbidden nebular lines tracing gas densities higher than 10 9  cm -3 , typical of the broad line region of active galactic nuclei. These spectral features indicate that GN-z11 hosts an accreting black hole. The spectrum also reveals a deep and blueshifted CIVλ1549 absorption trough, tracing an outflow with velocity 800-1,000 km s -1 , probably driven by the active galactic nucleus. Assuming local virial relations, we derive a black hole mass of log ( M BH / M ⊙ ) = 6.2 ± 0.3 , accreting at about five times the Eddington rate. These properties are consistent with both heavy seeds scenarios and scenarios considering intermediate and light seeds experiencing episodic super-Eddington phases. Our finding explains the high luminosity of GN-z11 and can also provide an explanation for its exceptionally high nitrogen abundance., (© 2024. The Author(s).)

Large dust reservoirs (up to approximately 10 8  M ⊙ ) have been detected 1-3 in galaxies out to redshift z ≃ 8, when the age of the Universe was only about 600 Myr. Generating substantial amounts of dust within such a short timescale has proven challenging for theories of dust formation 4,5 and has prompted the revision of the modelling of potential sites of dust production 6-8 , such as the atmospheres of asymptotic giant branch stars in low-metallicity environments, supernova ejecta and the accelerated growth of grains in the interstellar medium. However, degeneracies between different evolutionary pathways remain when the total dust mass of galaxies is the only available observable. Here we report observations of the 2,175 Å dust attenuation feature, which is well known in the Milky Way and galaxies at z ≲ 3 (refs. 9-11 ), in the near-infrared spectra of galaxies up to z ≃ 7, corresponding to the first billion years of cosmic time. The relatively short timescale implied for the formation of carbonaceous grains giving rise to this feature 12 suggests a rapid production process, possibly in Wolf-Rayet stars or supernova ejecta., (© 2023. The Author(s).)